When operating wind turbines, for instance in complex arrangements such as wind turbine parks, it is desirable to ensure a maximum of error-free operation. Thus, down times due to system faults need to be minimized, and also the time and effort necessary for maintenance and repair is to be kept as low as possible.
For ensuring error-free operation, systems designed according to the safe-life-approach are known in the art, for instance in aircraft design. Here, each particular component in the system is provided with a guaranteed life-time, after which the respective component is to be exchanged—the guaranteed life-time of a component being much lower than its actual life-time. While this approach provides for a very high reliability when the system is used, it requires a significant amount of maintenance, and thus, downtime. When, however, trying to reduce maintenance efforts, for instance by providing the system components with the highest possible life-time, the components need to be even further overdimensioned, so that the overall technical effort remains very high.
Another approach is known from published patent application US 2006/0100748 A1. Here a number of sensor/actor units is integrated with its respective control unit, so that the overall wind turbine control is modularized and each module is tightly coupled to its respective functional group. Consequently, when a first sensor/actor/control module becomes defective (or obsolete), it can be exchanged (or updated) without having to touch the remaining sensor/actor/control modules. Further, such a solution provides fail-safety features in view of fault isolation and fault containment. Regarding fault isolation, such a modularization enables proper identification of the faulty control module. Regarding fault containment, it potentially inhibits a control module failure (for instance, an electrical failure) from affecting further modules. A specific module of a first vendor could generally be exchanged for one of another vendor, without having to alter the remaining modules.